Mobile Computing Security

globedeepMobile - Wireless

Nov 24, 2013 (4 years and 6 months ago)


Mobile Computing Security
Protecting Data on Devices Roaming on the Perimeter
White Paper
Table of Contents
Executive Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 1
The Expanding Network Perimeter . . . . . . . . . . . . . . . . . . . . .Page 2
Securing the Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 3
Securing USB Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 4
Improving Mobile Security with Microsoft Vista . . . . . . . . . . .Page 5
Firewalls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 6
Encryption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 7
Protecting with Network Access Controls . . . . . . . . . . . . . . . .Page 8
Executive Summary
Notebook computers were once reserved for the executive sales force or those that really, truly had an organizational
need to be mobile . Today, the use of notebooks and other mobile computing devices has skyrocketed . In some
organizations, the notebook has eclipsed the desktop as the standard issue computing platform in order to enable
employees to take their work home with them and maximize productivity . In others, personal data assistants are the
computing platform de jour . But organizations need to put the proper tools in place to ensure that their mobile devices
and networks are not compromised as a result of this increase in mobility .
The Expanding
Network Perimeter
The traditional network perimeter is eroding,
or at least evolving . More and more users are
relying on notebook computers and other mobile
computing devices as their primary means of
productivity . Organizations can realize efficiency
and productivity gains by embracing mobile
computing, but they also need to comprehend
and defend against the unique security issues
introduced by mobile computing .
Mobile devices such as notebooks, personal
digital assistants, smartphones and USB storage
drives have become ubiquitous, and for an
increasing number of employees, their jobs would
be challenging without the mobility provided
by these devices . Nevertheless, poorly managed
mobile devices greatly increase the potential for
security failures and information compromise .
Stolen or lost notebooks, BlackBerrys, USB
sticks and other devices loaded with sensitive
information, such as confidential e-mails,
customer data and financial figures, can fall into
the wrong hands . The loss of highly sensitive
information and the potential associated
media scandal is a huge problem in itself,
but the impact might be greater — failure to
protect certain information can be construed
as a violation of regulations such as the Health
Insurance Portability and Accountability Act .
Desktop systems that exist inside the network
perimeter have the benefit of antimalware and
firewall protection implemented at the network
level, as well as the physical security present at
the office site . For mobile computing devices,
organizations have to ensure the device can
protect itself . Administrators need to implement
solutions at the device level to safeguard against
infection and unauthorized access, and protect
the data contained on the device .
In addition, administrators need to ensure that
the organization’s network is protected from
potential compromise from the wandering device
and wandering data . There are many ways
that confidential or private data can leave an
organization’s network . Users may copy files to
notebook PCs to take work home or copy data to
portable storage devices, such as Universal Serial
Bus flash drives, cell phones, digital cameras
or MP3 players . Data can be intentionally or
inadvertently sent out via e-mail, which makes it
tough to protect against information leakage .
The best way to protect the ever-expanding
network is to centralize data stores as much as
possible, secure devices and USB ports, protect
the network with firewalls and encrypt data . To
maximize this, follow these simple, but practical
mobile security best practices .
Network Threats
In a recent CDW

G poll, IT managers stated that
end-user data was the biggest threat to their
organizations’ networks .
Which layer of your organization’s network
security do you think is most vulnerable?
56% End-user data
19% Application layer
13% Network layer
8% Transport layer
4% Other

G poll of 324 IT leaders .
Best Practices:
Securing the Device
One of the first measures to protect a notebook
computer is to set or enable a BIOS or hard drive
password . This password is required when the
computer is turned on and provides security at
the hardware level before the operating system
even begins to boot . Beyond that, antimalware,
personal firewalls and wireless protocol
encryption provide multiple layers of security for
the mobile device .
Even on desktop systems inside the network
perimeter, most organizations have some sort of
client-level antimalware and personal firewall
solution in place . For roaming mobile devices
that have to protect themselves, these security
measures become even more imperative .
Download updates directly from
manufacturers: Administrators need to take
into consideration that the mobile device may
go days or weeks without connecting to the
organization’s, but it still needs to get the
latest signature updates . For mobile devices,
the software should be configured to download
updates straight from the manufacturers’ servers
rather than relying on internal servers on the
organization’s network .
Patch religiously: Monitor security patches
released by the manufacturers of the software
installed on your mobile devices . Just like on
the desktop, discovering and installing security
patches as soon as possible can significantly
reduce the number of security incidents .
Manage connectivity mechanisms: Turn off
Bluetooth when you are not using it . Do the
same with other connectivity mechanisms . Use
the highest possible security settings for wireless
connections .
Password-protect the device: Most devices
come with basic password protection for
device use . Turn it on . If possible, install third-
party applications that implement stronger
authorization mechanisms than basic login
passwords .
Use physical locks for notebooks: Physical
locks will prevent miscreants from picking up
your notebooks and walking away with them .
Provide physical locks to your employees, and
instruct them to use the locks whenever they
use the notebooks outside the organization’s
premises .
Securely wipe devices before retiring them:
Confidential information has been recovered
from mobile devices sold through online auction
sites . Needless to say, most of those cases have
been media disasters for the organizations
involved . It is not enough to just delete the files
before retiring devices — deleted files can be
recovered easily . Destroying data completely from
disks and making it unrecoverable is a difficult
job . Use enterprise-grade disk-wiping software
for all mobile devices before retiring them .
Use software designed to recover or destroy
lost or stolen devices: Software applications
are available that “phone home” or connect to
monitoring services and report their location
whenever they are connected to the Internet .
Such applications can help in tracking, locating
and recovering stolen or lost notebooks .
Some devices have a remote-wipe feature that
lets you remotely delete all data or perform a
hard reset if they are lost or stolen .
The Perfect Storm
Ben Rothke, a New York City senior security
consultant with International Network Services,
calls it the “perfect storm” — curious people,
ubiquitous high-speed Internet access and
overall poor security on the servers storing
that information . “When you put those three
factors together, they combine to create the
situation where confidential data can be quickly
leaked and shared with an enormous amount of
information . Once the data is shared in such a
manner, it is effectively impossible to get it back
in a secure state .”
Securing USB Ports
Portable media has always been an issue when
it comes to securing data . If you do not have
control over the data once it is stored on the
portable media, how can you monitor or control
where it goes or who has access to it? From
a security perspective, the confidentiality and
integrity of the data are both at risk once it
becomes portable .
When portable media meant 5 .25-inch-wide
square floppy disks that only stored 360KB
of data, the risk wasn’t quite as big . Not that
360KB isn’t enough to store some sensitive or
confidential information, but portable media
today increases the risk exponentially . Now,
users can store 8GB on a USB drive smaller than
their thumb . This increases the risk both from the
perspective that a user can house significantly
more data on portable media, and from the
perspective that the small thumb drives are
easier to lose or misplace .
USB flash drives also pose a malware risk . Users
may bring in USB flash drives that have been
compromised and unwittingly infect the network
with a virus, worm or other malware . Allowing
users to bring in unauthorized storage devices
and attach them to computer resources on the
internal network exposes your organization to
threats that bypass most, if not all, of the layers
of security in place to protect the network .
In addition to the risk of compromising data
or transporting malicious code, regulations
such as Sarbanes-Oxley, HIPAA or the PCI
Data Security Standards require that certain
types of information, especially personally
identifiable information and customer data, be
protected . Noncompliance or breaches of these
requirements can be quite costly .
It is important for organizations to understand
the risk posed by USB flash drives and other
removable media, and take proactive steps to
manage users’ ability to use them . The list below
details some things you can do to lock down
access for USB flash drives and protect your data
from the risks of portable media .
Written policy: The first step in reigning in the
use of USB flash drives and other portable media
is to define your policy in a written document .
Letting users know when, or if, or under what
conditions the use of USB flash drives is
acceptable will raise user awareness of the risks
and reduce your exposure .
Restrict access: You can use Group Policy to
restrict or deny access to prevent the computers
on your network from reading data from
or writing data to USB flash drives or other
removable media entirely .
Antimalware: You should have desktop-level
antimalware software in place and ensure that
it is updated regularly to detect current threats .
Antimalware software will scan and detect
threats before allowing a file on the USB flash
drive to execute, and it provides protection
against rogue USB flash drives infecting your
whole network .
Encrypt data: To prevent the compromise of
data in the event that a USB flash drive is lost or
stolen, implement security measures on the USB
flash drive itself, such as encrypting the data .
Rights management: By implementing
Windows Rights Management Services (WRMS),
you enable a much higher level of control and
flexibility in managing access rights for the data
on your network . WRMS allows you to control
not only whether groups or individuals are able
to view or modify a file, but also whether they
can forward or print the file . In addition, these
rights can be changed even after the data has
been downloaded and taken offsite .
The technology options for securing USB
ports and drives is growing, and includes
manufacturers such as GFI EndPoint Security,
Pointsec Device Protector and Media Encryption .
In addition to controlling access to USB ports,
port management tools may also control a
combination of FireWire, serial, printer and
infrared ports, floppy/CD/DVD drives, and USB-
connected Wi-Fi or Bluetooth adapters . Some
of the tools also let you restrict access for MP3/
media players, handhelds, and CompactFlash and
SmartMedia, as well as USB flash drives .
With port-blocking software, you don’t need to
physically remove, change or block any of your
computer hardware . Instead, simply install the
software — which may install small “agent”
programs on each computer to be controlled —
and assign appropriate privileges to each end
user . You shouldn’t need any new hardware to
run the administrative software, as one of your
current Windows computers should be sufficient .
The cost is likely to be in the $30 to $100 range
per computer — far less than the impact of any
security breach .
Unauthorized Devices
“Make sure your employees understand they
shouldn’t plug ‘foreign’ — nonauthorized
— devices into [organizational] computers,”
suggests Eric Ogren, security analyst with
Enterprise Strategy Group .
Does your organization currently use USB
flash drives?
55% Yes
44% No
1% Don’t know

G poll of 560 IT leaders .
Improving Mobile Security
with Windows Vista
Using Windows Vista as the operating system
for mobile devices also provides additional
security . Malware typically executes with the
privileges of the logged-in user . In many cases,
organizations have allowed users to have local
administrator privileges under Windows XP in
order to enable them to be able to make system
and configuration changes that they are unable
to do as standard users .
With Windows Vista, Microsoft addressed many
of the issues that standard users encountered
in Windows XP, enabling organizations to
enforce users logging in as standard user rather
than local administrator . In addition, one of
the features of UAC (user account control)
protects the system from being compromised
by malware even for users who are logged in
as administrator . Malware that would simply
execute for an administrator in Windows XP will
result in a consent prompt in Windows Vista,
alerting the user that something is attempting to
perform actions that may impact the system .
The whole point of UAC is to protect users and
their computer systems from themselves . The
standard user often does not have broad enough
permissions for many purposes, which leads
to users running with administrator privileges .
Without some other control or security measure
in place, a user running as administrator can
install software or make system changes
that have an adverse impact . Malware that
compromises the system typically runs in the
same context as the logged-in user, meaning that
the malware could also install software and make
system changes with administrator privileges .
With UAC, even administrators are greeted
with the Consent User Interface, or Consent UI .
Consent UI is just a catchy name for the pop-up
box that appears to confirm that you really want
to execute the program in question . Most of the
time, you will see the Consent UI alert message
immediately after you try to execute or install
some software . Because you initiated the action,
the Consent UI seems more like an annoyance
than a security measure .
In addition, Windows Vista includes additional
features that render virtually all existing malware
powerless . Most malware attacks rely on either
being able to identify where in memory certain
functions or processes are stored, or the ability
to exploit buffer overflows in data to execute
malicious code, or both . ASLR (Address Space
Layer Randomization) and DEP (Data Execution
Prevention) combine to eliminate these common
attack vectors . ASLR randomizes the memory
location of system functions, and DEP prevents
any code to execute from within file areas
designated for data .
Vista Encryption
Microsoft Vista relies primarily on AES (Advanced
Encryption System), using it as the encryption
algorithm for both EFS (Encrypted File System)
and BitLocker drive encryption . BitLocker can
be configured to use either 128-bit or 256-bit
AES encryption . IPSec encryption uses DES (Data
Encryption Standard) or 3DES, but provides the
ability to use a standard MD5 hash or an SHA-1
(Secure Hashing Algorithm) hash for the integrity
algorithm .
Restrict Access with
a Personal Firewall
Mobile devices should also be protected by some
form of personal firewall . Many security suites
include a personal firewall component that can
be used for mobile devices as well . As with the
antimalware component, the firewall software on
mobile devices should be configured to download
updates from a publicly accessible source rather
than relying on a connection to servers on the
internal network .
All data entering or leaving your organization
will pass through the firewall . It can keep out
unwanted intruders but also hamper critical
connectivity . For example, your firewall may
interfere with links to your website (if hosted
locally or not), access to other websites, remote
virtual private network users, wide area network
connections, Internet updates and Voice over
Internet Protocol telephone calls . It may also
interact with server certificates, web e-mail,
handheld device connections and domain name
system requests .
To make sure you understand what you want
your future firewall to keep out, thoroughly
catalog and prioritize all your needs . There may
not be a system within your price range that
meets all of your diverse needs, and ultimately
some things may need to be left out or more
money must be budgeted . But there is another
dark and insidious reason: maintaining VPN
services .
Once a VPN is available, users expect it to
work at all times from all locations, yet not
all firewalls will accept a connection from the
built-in Microsoft Windows client . Additionally,
some firewalls on the remote end will block VPN
connections . Meanwhile, your remote users may
instinctively seek out locations around the globe
where a VPN connection is nearly impossible and
then call in asking that you remedy the situation .
Today unified threat management firewalls
add a range of security functions that have
typically been available piecemeal as separate
programs or devices, from virus protection to
spam, phishing and spyware blockers . On the
menu of UTM features, buyers can find intrusion
prevention systems (IPS); content filtering
functions; programs to block spam, spyware
and phishing attempts; and even vulnerability
scanning — software that probes for potential
security gaps based on a network’s defenses and
known vulnerabilities . Yet every manufacturer
offers a different mix of services in their UTM
cocktail, and the mix can vary within a single
manufacturer’s product line . For example,
WatchGuard’s Firebox X family of security
appliances can run either the standard Fireware
or Fireware Pro operating systems, but IPS and
antispyware capabilities are only available on the
Pro version . Figuring out the menu of available
services isn’t hard, but anticipating future as
well as current needs is critical . In many cases
with the smallest devices, UTM features and
expansion capabilities may be severely limited .
In all its various flavors, UTM carries a clear
promise: more security that is easier to manage,
requires fewer boxes and provides higher
reliability . It’s an obvious advance that has
pushed every significant firewall manufacturer
to jump on the UTM bandwagon . Calculating
security return on investment is a difficult game:
Estimating money saved by not suffering a
network breach or other security meltdown can
be next to impossible . But the new generation
of UTM firewalls offers a better deal, combining
a range of services into a single box that’s
economical to purchase and easy to manage .
Even if there is not a third-party personal firewall
solution, mobile devices using Windows XP or
Windows Vista include the Windows Firewall . The
Windows Firewall in Windows Vista restricts both
inbound and outbound access and provides more
granular control than its predecessor, but given
the alternative of using nothing at all, even the
Windows Firewall in Windows XP affords some
protection for mobile devices .
All three products inspect the network layer,
opening and closing ports like any router would,
but they also each perform stateful filtering,
which works at the transport layer and inspects
packets for their intended destination . If that
destination did not request that particular
packet, it gets rejected . This type of stateful
inspection lets the systems administrator block
any information to or from a particular address .
At the application layer, these products also
will inspect entering and departing packets for
inconsistencies and patterns in the application
layer, which would indicate problems such as
potential network attacks .

Firewall Options
Three popular firewall options include
SonicWall’s Pro 2040 Standard, Cisco’s Adaptive
Security Appliance 5510 and WatchGuard’s
Firebox X 550e . Cisco offers a Secure Sockets
Layer VPN option .
All three options inspect the network layer,
opening and closing ports like any router would .
But they also each perform stateful filtering,
which works at the transport layer and inspects
packets for their intended destination . If that
destination did not request that particular
packet, it gets rejected . This type of stateful
inspection lets the systems administrator block
any information to or from a particular address .
At the application layer, these products also
will inspect entering and departing packets for
inconsistencies and patterns in the application
layer, which would indicate problems such as
potential network attacks .
Encrypting the entire disk or other storage is
probably the most important thing you can do
to prevent the theft of confidential information
from a mobile device . An encrypted disk will
be the final layer of defense in case a device
falls into the wrong hands . Good encryption
makes the data inaccessible to illegitimate users .
Many commercial software applications do
this automatically while remaining completely
transparent to the user . Another, albeit weaker,
approach is to encrypt individual sensitive files
and folders instead of encrypting the entire
disk . This tactic can be used in situations where
encrypting the entire disk is not an option .
Configure the devices to always use the highest
available encryption standard for wireless
connections . All connections to the internal
organizational network must be over a virtual
private network .
Encrypting Wireless Communications
Mobile devices are commonly used to connect
to wireless networks . The wireless network may
be at the office, at home, in a hotel, or at the
coffee shop on the corner . Wireless networking
is convenient but also represents unique security
concerns . Namely, anybody within range can
intercept the data as it is beamed through the air .
To protect the data being transmitted to and
from the mobile device, a wireless encryption
protocol such as WPA2 should be used whenever
possible . In addition, any connections from
outside of the network should only be allowed
via a secured connection such as an encrypted
VPN tunnel . At public hotspots that are not
configured for encryption, users must be aware
that their data is unprotected and exercise
caution in the types of sites they visit and the
information they transmit across the network .
Encrypting the Data
If you read the news headlines, it seems as
if there isn’t a week that goes by without
some security breach resulting from a lost or
stolen notebook . The rise in the use of mobile
computing devices brings with it a rise in the
number of lost and stolen mobile computing
devices and a need to implement some protection
for the data contained on the mobile device in
the event it falls into unauthorized hands .
Many organizations have implemented or are
looking to implement drive encryption to protect
all of the data contained on the mobile device .
This is especially true for those organizations
in specific industry segments like the financial
or health sectors which have more stringent
compliance regulations .
Checkpoint and McAfee offer two of the
more widely known disk encryption solutions .
Checkpoint’s disk encryption was formerly
known as Pointsec, and McAfee’s solution was
previously SafeBoot . Again, organizations that
have deployed Windows Vista for their mobile
devices have an advantage because it comes
with BitLocker Drive Encryption built in so there
is no need to invest additional money in an add-
on third-party product .
BitLocker works with the Trusted Platform
Module, a chip used to provide additional
security functionality that’s permanently attached
to a system’s motherboard . Tying the encryption
key to the hardware and the validation process of
TPM means hackers cannot modify or bypass the
encryption — a problem with other encryption
tools Microsoft has offered . Previous Windows
versions have included data encryption features,
such as Encrypted File System (EFS), but the
tools protected only files and folders . An attacker
could boot another OS, such as the Knoppix
Linux distribution, to access and crack a system’s
password store . Once the system authenticates a
hacker, EFS cannot provide protection .
Other Windows encryption tools have relied on
the user to decide what should or should not
be encrypted . Even if a systems administrator
creates a special encrypted folder on a drive
specifically to hold confidential or sensitive
data, there’s no way to be sure that users put all
appropriate data in the folder . In the event of a
notebook theft, the organization would still be
unable to guarantee that private or personally
identifiable information was not exposed .
But encrypting the entire drive removes the
guesswork .
Network Access
Whichever NAC option your organization selects,
it’s important that they consider standards .
The three competing standards — Microsoft’s
Network Access Protection (NAP), Cisco’s NAC
and Trusted Computing Group’s Trusted Network
Connect (TNC) — have begun to merge, but
users may find some early compatibility gaps
when they mix products from the more than
200 vendors that have licensed the three
technologies . But compatibility is the goal . In
October 2006 Microsoft and Cisco announced
they had developed an interoperability
architecture that lets NAP- and NAC-compatible
products work together . Then, in May 2007,
Microsoft said it would make NAP compatible
with TNC, which is an open standard . NAP is
built into Microsoft Vista and is available in
Windows Server 2008 .
Protecting the Network
Eventually the wandering mobile device will return to base and want
to connect with the home network directly . In order to protect the
internal network from any system compromises or nasty malware
infections the mobile device may have picked up while it was away,
it is a good idea to have some sort of NAC (Network Access Control)
solution in place .
NAC products will analyze the mobile device (and any other device
connecting to the network) and ensure that it is patched, has the
appropriate security software installed, running and up to date, and
that it otherwise meets the organization’s security policy requirements
before allowing it to connect to internal network resources . Most
NAC solutions offer an option between simply rejecting connections
from noncompliant clients, or redirecting them to a site or server with
information and resources to enable the device to become compliant .
NAC is more than a mere firewall that grants recognized computers
access, or a password scheme that lets privileged members log on .
At its best, NAC ensures that any notebook computer, server or
handheld device trying to access the network has up-to-date antivirus
software and meets specified security standards . This is done by
software agents sent by the NAC to check approaching machines
for antivirus, antispyware and installed patches, as well as complex
system characteristics, such as registry entries and file attributes .
Computers that aren’t deemed safe are barred entry or are redirected
to a quarantined site where network administrators can update the
computer’s software or tell its user where to do so .
Network Attacks
Mobile devices must also be protected against network-based attacks .
Mobile devices (notebooks running off-the-shelf operating systems,
for example) are vulnerable to the same varieties of attacks as any
other computer system .
Because they need to operate in foreign networks, such as coffee
shops, airport kiosks or other hotspots, mobile devices have extra-
stringent security needs . They can’t rely on the organization’s firewall
for protection . And the organization needs a means of managing
security configuration, patch deployment and antivirus updates on
their devices in the field .
Even systems running special-purpose operating systems have some
vulnerabilities . Forced de-authentication attacks, in which an attacker
transmits packets intended to convince a mobile end-point to drop its
network connection and reacquire a new signal, can insert a rogue
infrastructure device between a mobile device and the legitimate
network .
Another security concern is the ability of many mobile devices to
operate utilizing multiple protocols . They may primarily use one of the
802 .11 family protocols or a cellular provider’s network, but chances
are good that they can also communicate via infrared or Bluetooth .
Even if those protocols aren’t in active usage, many devices have
these interfaces set “active” by default . Attackers can take advantage
of this vulnerability and connect to the device, allowing them access
to extract information from it or use its services . It’s important for
mobile device users to take the step of securing each of their device’s
communications interfaces . ◆